barack obama was president already so by definition he's been filtered for four years but mitt romney was he extreme or filtered? >> guest: of filtered. one term as governor and in the historical perspective and politics had he won the presidency, he would have been second only to wilson and arguably grover cleveland depending on how you look at it in terms of the shortness in the political career before he became president. >> host: thank you. this is a fascinating book. it looks that a lot of stuff that you know what it tells you stuff you don't know. thanks very much. >> guest: thanks very much. >>> our interviewed by journalists, public policy makers, legislators and others familiar with the material. "after words" is a free weekend 10 p.m. on saturday, 12 and 9 p.m. on sunday and 12 a.m. on monday. you can also watch online, go to booktv.org and click on "after words" in the book tv series and topics list on the upper right side of the page. >>> here is a look at some books being published this week. and when >>> historian harlow giles unger recounts the life of america's sixth p